It is known from the prior art to provide fluids in sealed flexible, plastic containers. Such fluids are often medically related. Such containers usually contain an access port affixed thereto. This access port can be opened by means of a suitable connector in order to deliver the fluids within the container to a patient.
The seals used with such containers are often cylindrical with a pierceable, closing membrane affixed to an interior peripheral surface of the cylindrical member. The cylindrical member can be affixed to the access port of the container in a variety of ways.
One method known from the prior art is to use a plastic solvent which softens and melts an exterior, peripheral surface of the cylindrical seal member as well as an interior cylindrical surface of the port of the container. The seal member is inserted into the cylindrical port. Upon evaporation of the solvent, a fluid resistant bond is formed between the two members.
Alternately, the seal member can be inserted into the cylindrical port. An electrically, energizable mandrel can be inserted through an open seam or peripheral edge of the container and into the seal member. An external radio frequency electrode can be positioned outside of the container, adjacent the port. Supplying an electrical potential at a selected radio frequency between the inner mandrel and the outer electrode creates a heating electric field which extends radially through the port and through the cylindrical sealing member to the mandrel.
This radio frequency electrical field heats the material of the port as well as the cylindrical sealing member in the region of the electrode. The heated materials melt and fuse together thereby creating, on cooling, a liquid resistant bond between the seal member and the port of the container.
While the above two noted methods provide effective liquid resistant seals, there are times when it would be useful to be able to affix a sealing member to a port of a closed container without the use of a solvent. If the container is closed, there is no opening available to insert a mandrel therein as described above. Hence, there is a need for a radio frequency sealing method usable with containers having a closed peripheral boundary. These containers may or may not have been previously filled with a fluid.